I made more sunshine

Everyone knows that to make electricity, solar panels (often formally called “photovoltaic”, or “PV” panels) need to have daylight, ideally full sun. This is why solar panels don’t produce much electricity on cloudy days—and none at all at night. The number of daylight hours matters, too, which is why the panels make more electricity in the summer than in winter. And, of course, bright sunny days are the absolute best days for solar power. But, what if the amount of sunshine, whatever it is, is shielded? I just took steps to increase the amount of sunshine hitting my panels, and so, the amount of electricity they make.

Not for the first time, I learned about the existence of something through Facebook ads. In this case, it was about the importance of having solar panels cleaned in order to maximise the amount of electricity the panels create. Last week, I had a specialist company clean my panels, and yes, it was worth it.

The company also cleans large banks of panels for commercial operations, so I had confidence they knew what they were doing—though the reviews I checked were also all positive. They do a thorough check of the system, for example, making sure none of the glass is cracked, that the mounts are secure, and that the inverter (which converts the DC power from the panels into AC power used by the house or sent to the grid) is functioning properly.

The specific thing that caught my attention in the ads was about removing lichen—something I’d never considered. A few weeks ago, I looked at my panels and realised they had lichen growing on them, which is like little pads of shade all over the panels. I also noticed they were dirty.

At first, I thought about getting an extra long-handled washing brush, the type typically used for washing windows on upper floors while standing on the ground. I realised, though, that I’d probably still have to climb a ladder, something everyone in the family thought was a bad idea. Hiring someone was the alternative.

The Before and After photos up top are part of what I posted to social media, and the ones at the bottom of this post were taken by the person who cleaned the panels, looking down the roof toward the ground, an angle I’d never seen before. The whole process took a couple hours or so, and I didn’t need to be at home for them to do it.

And, yes, it was worth it.

I looked at the information my inverter logs to see of there was an obvious difference in electricity production, but I needed to figure out the best way to compare, given that this is Spring, and the weather is so changeable. So, I just looked at the four highest-production days before the cleaning and the four highest afterward—but not including the day they were cleaned—and averaged them for both periods. After cleaning, the panels were producing just under 20% more power than before they were cleaned, which is quite significant. Before the panels were cleaned, the highest production day made 26.30 kWh of electricity, and the highest after they were cleaned was 31.51 kWh.

The more power that’s generated, the bigger the potential financial benefit—obviously. I benefit mainly from getting free electricity to used in the daytime, and anything I don’t use is sent to the grid, earning me credits to reduce the amount I pay for electricity thre rest of the time. This is where the inverter stats became unreliable—but still interesting.

The inverter tracks all the electricity I produce, of course, and the software estimates my “savings”, which is an estimate of the amount of money I’ve saved from using the solar power myself and from the credit I get for the power I send to the grid. However, to be accurate, they need to use an accurate rate—called a “tariff”—to make the calculations, and I don’t know whether the rates are accurate or not. So, with that rather huge caveat, the estimate on the fourth post-cleaning day was that from the date the system went live three years ago until the fourth day after cleaning, my savings totalled $5,955.30, of which $1,121.57 was just for 2025 to that date (and October’s savings to that date were $87.53). While I doubt those numbers are accurate, if they were, it would mean that the savings have recovered nearly half of what I paid to install the system. Regardless, the free power I use on sunny days does save me a lot of money.

I clearly take all the information about savings with a huge grain of salt. I plan to try to work out how accurate their calculations are, but that’s a project for future me. In the meantime, I just think it’s interesting.

The bottom line—literally—is that keeping the panels clean means more electricity generated, and that, in turn, means more savings for me (whatever the amount is…). Most importantly, all this also means that I don’t “waste” any electricity I use in the daytime, which was really the main thing I wanted, because it achieves my goal of treading more lightly on the planet. Everybody wins—including the planet.